Demo: The "Denpa" Men: They Came by Wave (Genius Sonority, 1 player, free): Use your 3DS to find hidden men in spandex suits who are constantly watching you every day, all day. Also, have fun going to bed tonight knowing that!

DSiWare

Retro Pocket (UFO Interactive, 1 player, $4.99/500 DSi Points on DSiWare): A modern take on retro LCD games like Mr. Game & Watch and every single Tiger Electronics handheld game ever made.